/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.nexmark.queries;



import com.bff.gaia.unified.sdk.nexmark.NexmarkConfiguration;

import com.bff.gaia.unified.sdk.nexmark.NexmarkUtils;

import com.bff.gaia.unified.sdk.nexmark.model.Auction;

import com.bff.gaia.unified.sdk.nexmark.model.Event;

import com.bff.gaia.unified.sdk.nexmark.model.IdNameReserve;

import com.bff.gaia.unified.sdk.nexmark.model.Person;

import com.bff.gaia.unified.sdk.values.TimestampedValue;

import com.bff.gaia.unified.vendor.guava.com.google.common.collect.ArrayListMultimap;

import com.bff.gaia.unified.vendor.guava.com.google.common.collect.Multimap;

import org.joda.time.Duration;

import org.joda.time.Instant;



import java.io.Serializable;

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;



/** A direct implementation of {@link Query8}. */

public class Query8Model extends NexmarkQueryModel<IdNameReserve> implements Serializable {

  /** Simulator for query 8. */

  private class Simulator extends AbstractSimulator<Event, IdNameReserve> {

    /** New persons seen in the current window, indexed by id. */

    private final Map<Long, Person> newPersons;



    /** New auctions seen in the current window, indexed by seller id. */

    private final Multimap<Long, Auction> newAuctions;



    /** When did the current window start. */

    private Instant windowStart;



    public Simulator(NexmarkConfiguration configuration) {

      super(NexmarkUtils.standardEventIterator(configuration));

      newPersons = new HashMap<>();

      newAuctions = ArrayListMultimap.create();

      windowStart = NexmarkUtils.BEGINNING_OF_TIME;

    }



    /** Retire all persons added in last window. */

    private void retirePersons() {

      for (Map.Entry<Long, Person> entry : newPersons.entrySet()) {

        NexmarkUtils.info("retire: %s", entry.getValue());

      }

      newPersons.clear();

    }



    /** Retire all auctions added in last window. */

    private void retireAuctions() {

      for (Map.Entry<Long, Auction> entry : newAuctions.entries()) {

        NexmarkUtils.info("retire: %s", entry.getValue());

      }

      newAuctions.clear();

    }



    /** Capture new result. */

    private void addResult(Auction auction, Person person, Instant timestamp) {

      addResult(

          TimestampedValue.of(

              new IdNameReserve(person.id, person.name, auction.reserve), timestamp));

    }



    @Override

    public void run() {

      TimestampedValue<Event> timestampedEvent = nextInput();

      if (timestampedEvent == null) {

        allDone();

        return;

      }



      Event event = timestampedEvent.getValue();

      if (event.bid != null) {

        // Ignore bid events.

        // Keep looking for next events.

        return;

      }

      Instant timestamp = timestampedEvent.getTimestamp();

      Instant newWindowStart =

          windowStart(

              Duration.standardSeconds(configuration.windowSizeSec),

              Duration.standardSeconds(configuration.windowSizeSec),

              timestamp);

      if (!newWindowStart.equals(windowStart)) {

        // Retire this window.

        retirePersons();

        retireAuctions();

        windowStart = newWindowStart;

      }



      if (event.newAuction != null) {

        // Join new auction with existing person, if any.

        Person person = newPersons.get(event.newAuction.seller);

        if (person != null) {

          addResult(event.newAuction, person, timestamp);

        } else {

          // Remember auction for future new people.

          newAuctions.put(event.newAuction.seller, event.newAuction);

        }

      } else { // event is not an auction, nor a bid, so it is a person

        // Join new person with existing auctions.

        for (Auction auction : newAuctions.get(event.newPerson.id)) {

          addResult(auction, event.newPerson, timestamp);

        }

        // We'll never need these auctions again.

        newAuctions.removeAll(event.newPerson.id);

        // Remember person for future auctions.

        newPersons.put(event.newPerson.id, event.newPerson);

      }

    }

  }



  public Query8Model(NexmarkConfiguration configuration) {

    super(configuration);

  }



  @Override

  public AbstractSimulator<?, IdNameReserve> simulator() {

    return new Simulator(configuration);

  }



  @Override

  protected Collection<String> toCollection(Iterator<TimestampedValue<IdNameReserve>> itr) {

    return toValue(itr);

  }

}